Over time cathodic protection replaces the negative chloride (Cl-)ion with dissolved bicarbonate (HCO3-) to harden the coating to a hydromagnesite-aragonite mixture with gaseous oxygen being evolved through the porous structure. This hardened, concrete-like structure for a habitat for coral growth.

Some electrical energy will be used for the cooler to cool the water to the suitable temperature (20°C ) by moving water into the cooler, cooling it, and returning it to the tank.

Nourishment + Respiration: Corals obtain nourishment from the zooxanthellae living in and among it (The zooxanthellae are algae that carry out photosynthesis, thus they require sunlight. After photosynthesis, sugars and oxygen are produced.)

Zooxanthellae: zooxanthellae are algae that carry out photosynthesis (require sunlight), thus they convert sunlight (clear water is then required), water and carbon dioxide (product from coral’s respiration) into sugars (for nourishment of corals) and oxygen (for respiration of corals)

Water Temperature: corals generally thrive in temperatures ranging from 20°C to 32°C

Clean Water: sediments can harm the corals and block sunlight from reaching the zooxanthellae; wastewater can result in too much nutrients and consequently overgrowth of seaweeds, also blocking the sunlight from reaching the zooxanthellae

Saltwater: corals require a certain ratio of salt to water

2.5 Risk Assessment and Management

Risk

Assessment

Management

There are wires and batteries that have to be placed near water. If there is a short circuit, and someone puts his/her hand in the water, he/she may be electrocuted.

High

Before having contact with any parts, ensure no breaks or tears in the wires.

Always wear thick rubber gloves when putting hands in water, as rubber is an insulator of electricity.

Some corals may be rough/sharp, and even poisonous.

Medium

Always wear thick rubber gloves when putting hands in water.

The solar panel might not be enough to support the whole experiment.

Medium

Test out without the solar panel and take down the data before using the actual solar panel.

The hot wires might burn or injure us.

As seen in the picture above, faulty wires are hot enough to burn through the plastic covering of the crocodile clips got burnt through. This shows that the wire is very hot, and thus we need to be very careful when handling them as they might burn you.

Medium

Wear protective gloves when soldering.

Legend

Low

Unlikely and not severe harm

Medium

Likely but not severe OR Unlikely but severe

High

Likely and Severe harm

2.6 Data Analysis

Measure the mass of the anode and cathode daily

Plot a graph/fill in a table to show the changes in the mass, and whether it makes sense

When we find out that the wire mesh (cathode) did increase in mass, we inferred that if we made a large-scale version of our setup, it would be sufficient to house corals, rebuilding coral reefs.